Absorption refrigeration



I the resulting liquid is vaporized at reduced pres- Patented May 19, 1936 UNITED STATES PATENT 0FFlCE ABSORPTION REFRIGERATION Glenn F. Zellhoefer, Bloomington, Ill.

No Drawing. Application May 3, 1935, Serial No. 19,599

2 Claims.

throughout the operation of the apparatus, and

a refrigerant material adapted to have a liquid and a vapor phase in the cycles of operation, adapted to be dissolved or absorbed in the solvent, adapted to be evaporated or boiled as a vapor from the solvent mixture and from the solvent, and adapted to be condensed from the vapor to a liquid. Numerous refrigerants and numerous solvents are known, as well, as successful combinations of these.

The two-fluid absorption machines have certain mechanical parts which may be omitted or which are not duplicated in three-fluid machines; In a three-,fluid'machine, there is, in addition to the two-fluid mixture, a body of inert gas which is always gas, and which does not to any substantial extent dissolve in any of the components of the two-fluid composition, or in mixtures thereof.

The present invention is directed to anew solvent for absorption refrigeration, and to combinations thereof with refrigerants.

A particular object of the invention is the use 'of dimethyl ether of hexaethylene glycol as a. solvent.

Another object is the use of a combination of said solvent with the refrigerant, dichioromonofluoromethane.

Examples of the two-fluid apparatus in which the new solvent material and the new combination may be used is' disclosed in my co-pending application Serial No. 651,306, filed January, 12, 1933, or in my U. S. Patent No. 1,895,698, issued January 31, 1933. Other examples may readily be cited, and will be known to those skilled in the art.

The two-fluid apparatus above referred to, briefly described, comprises a still in which a liquid mixture of solvent and refrigerant is heated to distill away as a vapor the refrigerant ma- .terial, a condenser wherein said vapor is condensed to a liquid state, an evaporator wherein sure to produce refrigeration, and an absorber in which vapor of the refrigerant material containing added heat units (acquired in the rei'rigerating process) is again dissolved in the solvenii material. Suitable heat exchanging-and circulating means are included, and automatic controls may be provided.

The particular characteristics of such a machine are that the still operates .at temperatures well above normal temperatures, such for example at 210 F. to 250 F.; and that the cooling unit operates at temperatures lower than normal, such as from 15 1". to 50 1". Various parts of the apparatus diflfer in the prevailing temperatures and pressures, and both pressure and temperature determine the physical state of the free refrigerant material, whether gaseous or liquid, and determine the solubility relations between the refrigerant and the solvent material. It is, there-,

fore, very important that the solvent and the refrigerant materials be physically adapted for use as individual materials in certain places and for certain functions, and that they be mutually adapted for certain functions when they are in combination. Other qualities not essential to refrigeration, but pertinent to practical usage, con-* trol or limit the choice of solvent or refrigerant,

such as odor, viscosity, heat capacity, boiling point, freezing point, volatility, chemical stability, reactivity, corrosive action, inflammability, toxicity,'etc.

By considering the limitations herein set forth and suggested,- I have been able to utilize dimethyl ether of hexaethylene glycol as a solvent, for

practical usage, in combination with the refrigerant, dichloromonofluoromethane, which is little known.

The new solvent is herein named as dimethyl ether of hexaethylene glycol. In order to leave A .no doubt as to its identity, its structural formula,

ple adulteration of the new solvent in its pure,

form, either by reason of commercial impurities,

or by addition of lesser quantities of other material, useful also as solvent, is permitted, and

such a composition is intended to fall within the scope of the present invention.

What I claim is:

The solvent herein specifically claimed is .covered generically in applicants copending applicav tion Serial No. 17,064, filed April 18, 1935.

1. A refrigerant mixture for the absorption type of refrigeration apparatus consisting of dimethyl ether of hexaethylene glycol as the essentially predominant solvent, and dichloromonofluoromethane as a refrigerant.

2. A refrigerant mixture for the absorption type of refrigeration apparatus consisting of dimetbul ether of hexaethylene glycol as the essentially predominant solvent, and a volatile chemically stable halogenated hydrocarbon refrigerant soluble in said solvent.

I GLENN 1". ZEILHOII'IR. 

